Model Test Study Of Leading Edge Anti-tilt And Locked Landslide

Landslides are a common geological disaster,which often cause traffic interruption,river blockages,and blocked construction,which seriously threaten people's lives and property.Lock-up landslides generally have the characteristics of concealment,suddenness and high-speed long-distance,and disaster losses are more serious.Therefore,research on lock-up landslides has important theoretical significance and engineering practice significance.In this paper,a field survey of Huaipa landslide in Mianchi County was conducted,and it was found that there is a rock layer opposite the slope angle at the front edge of the slope,which provides the main bearing effect for landslide deformation.Based on field engineering geological survey data,a leading-edge anti-tilt and lock-type landslide generalized test model was constructed,and rainfall-induced landslide model tests of lock-type and un-locked sections were conducted.The instability mechanisms and deformation failure modes of the two types of slopes are analyzed,and the results of model tests are analyzed using numerical simulation methods.The main results of the paper are as follows:(1)The topography,geomorphology,rock and soil types,geological structures,and groundwater engineering geological conditions of the landslide area were ascertained.The genesis mechanism of the landslide was qualitatively analyzed.(2)Model tests on locked and unlocked rainfall-induced landslides were carried out.The test results are as follows.The leading edge anti-tilt locking landslide is sliding failure at the trailing edge,and its deformation failure mode is rainfall begins—rainwater infiltration,soil strength decreases—pore water converges to the leading edge of the slope—front edge soil strength decreases—the trailing edge of the slope sinks—the leading edge of the soil appears to push up—overall slope instability.The landslide in the unsecured section is traction sliding failure at the leading edge,and its deformation failure mode is rainfall begins—rainwater infiltration,soil strength decreases—tensile cracks on the slope—soil collapse along tensile cracks—overall sliding of the middle and rear soil—overall slope instability.(3)Under the condition of heavy rainfall,the leading edge of the anti-tilt locking landslide at the leading edge subsided,a crack occurred in the middle,and the soil at the leading edge of the slope deformed and destroyed.With the continuous rainfall,the effective strength of the soil at the front edge of the slope decreases,resulting in the overall instability of the slope.The soil at the leading edge of the landslide in the unsecured section generates tensile cracks under the action of rain erosion,infiltration and gravity.The soil at the front edge of the slope collapses along the tensile cracks,and the collapse range reaches the middle of the slope,and then the slope slides as a whole.(4)The finite element numerical simulation method is used to construct a numerical calculation model.The numerical analysis results are compared with the model test results.